This model compares two resistive loads. Model R consumes or produces
a variable amount of power, while model R1 consumes a fixed power.
At time t=0 R and R1 consumes the same amount of power
while at t=1 R produces the same power consumed by R1.
P_nominal as
this parameter is disabled and assigned a value
in the initial equation section.
This is for
issue 426.